The Rolls-Royce Exe, or Boreas, was a 24-cylinder air-cooled X block

sleeve valve The sleeve valve is a type of valve mechanism for piston engines, distinct from the usual poppet valve. Sleeve valve engines saw use in a number of pre-World War II luxury cars and in the United States in the Willys-Knight car and light truck. ...

aircraft engine An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Most aircraft engines are either piston engines or gas turbines, although a few have been rocket powered and in recent years many ...

intended primarily for the new Fairey

Fleet Air Arm The Fleet Air Arm (FAA) is one of the five fighting arms of the Royal Navy and is responsible for the delivery of naval air power both from land and at sea. The Fleet Air Arm operates the F-35 Lightning II for maritime strike, the AW159 Wil ...

aircraft, particularly the

Fairey Barracuda The Fairey Barracuda was a British carrier-borne torpedo and dive bomber designed by Fairey Aviation. It was the first aircraft of this type operated by the Royal Navy's Fleet Air Arm (FAA) to be fabricated entirely from metal. The Barracuda ...

. The Exe was relatively powerful for its era, producing about . This is notable given the relatively small displacement, the

Merlin Merlin ( cy, Myrddin, kw, Marzhin, br, Merzhin) is a mythical figure prominently featured in the legend of King Arthur and best known as a mage, with several other main roles. His usual depiction, based on an amalgamation of historic and le ...

requiring for approximately the same power level. The X-24 layout made this quite a compact engine. The Exe was named after the

River Exe The River Exe ( ) in England rises at Exe Head, near the village of Simonsbath, on Exmoor in Somerset, from the Bristol Channel coast, but flows more or less directly due south, so that most of its length lies in Devon. It flows for 60 mile ...

, although Rolls-Royce later transferred the use of river names to its

gas turbine A gas turbine, also called a combustion turbine, is a type of continuous flow internal combustion engine. The main parts common to all gas turbine engines form the power-producing part (known as the gas generator or core) and are, in the directi ...

engines.

Design and development

The Exe was under development in 1939, having been started in the 1930s, along with the Peregrine and

Vulture A vulture is a bird of prey that scavenges on carrion. There are 23 extant species of vulture (including Condors). Old World vultures include 16 living species native to Europe, Africa, and Asia; New World vultures are restricted to North and ...

. Work on the Exe was suspended in August 1939, and stopped about August 1940.

Ernest Hives Ernest Walter Hives, 1st Baron Hives (21 April 1886 – 24 April 1965), was the one-time head of the Rolls-Royce Aero Engine division and chairman of Rolls-Royce Ltd. Hives was born in Reading, Berkshire to John and Mary Hives, living at 31 C ...

, head of the Rolls-Royce aero engine division, wanted to stop work on the Exe, Peregrine, and Vulture to concentrate on the Merlin and Griffon engines. An enlarged version, the

Rolls-Royce Pennine The Rolls-Royce Pennine was a British 46-litre air-cooled sleeve valve engine with 24 cylinders arranged in an X formation. It was an enlarged version of the 22-litre Exe; a prototype engine was built and tested, but never flew. The project ...

, was built later in the war, but cancelled as

jet engine A jet engine is a type of reaction engine discharging a fast-moving jet of heated gas (usually air) that generates thrust by jet propulsion. While this broad definition can include rocket, Pump-jet, water jet, and hybrid propulsion, the term ...

s became the company's focus. Originally intended for the

Supermarine Type 322 The Supermarine Type 322 was a prototype British carrier-borne torpedo, dive bomber and reconnaissance aircraft of the Second World War. A single-engined monoplane, it was unsuccessful, with only two examples being built. The Fairey Barracuda, ...

and

the Exe was only test flown in a

Fairey Battle The Fairey Battle is a British single-engine light bomber that was designed and manufactured by the Fairey Aviation Company. It was developed during the mid-1930s for the Royal Air Force (RAF) as a monoplane successor to the Hawker Hart and Hi ...

, the first flight taking place on 30 November 1938. This aircraft continued in use for some time as a communications aircraft where the Exe was noted to be quite reliable in service.Rubbra 1990, p.148.

Applications

(intended) *

(testbed) *

(intended)

Specifications (Exe)

References

Notes

Bibliography

* Gunston, Bill. ''World Encyclopaedia of Aero Engines''. Cambridge, England. Patrick Stephens Limited, 1989. * Lloyd, Ian ''Rolls-Royce: The Merlin at War'' (1978, Macmillan London) * Lumsden, Alec. ''British Piston Engines and their Aircraft''. Marlborough, Wiltshire: Airlife Publishing, 2003. . * Pugh, Peter.''The Magic of a Name: The Rolls-Royce Story, The first 40 Years'' (2000, Icon Books Cambridge) * Rubbra, A.A. ''Rolls-Royce Piston Aero Engines - a designer remembers: Historical Series no 16'' :Rolls-Royce Heritage Trust, 1990.

External links

Photo of the Rolls-Royce Exe

in a 1948 issue of ''Flight'' {{RRaeroengines

Exe Exe or EXE may refer to: * .exe, a file extension * exe., abbreviation for executive Places * River Exe, in England * Exe Estuary, in England * Exe Island, in Exeter, England Transportation and vehicles * Exe (locomotive), a British locomotive ...

1930s aircraft piston engines X engines